This isn't about proceded 335i vs. 350Z. Hell, for 7K you can get the Greddy TT kit that makes 700HP at the wheels and rape any proceded 335i and still be 8K less.
Until there are MORE posted timeslips with stock 335is that are lower than 13.2, the facts are simply that it is a drivers race. Actually, fwiw, the two fastest stock 335i on dragtimes is 13.2 but the fastest with street tires is 13.4 which is slower than the three fastest street tired 350Z on the other website. So, from a DIG for a 1/4 mile, stock vs. stock. If I were a betting man, I'd actually bet the 07 350Z would win. Funny thing is that on dragtimes, there are no posted 07 350z's so maybe there are some good 335i stock times not posted? Anybody with the 335i beat 13.4 with street tires and all stock?